A dart board (target) is basically comprised of cork or other material intended to receive and hold the needle portion of the dart upon throwing thereof and wires arranged in various positions to determine point scoring areas on a dart board. Frequently it occurs that darts are thrown slightly off the desired target area and they contact the wire portion of the dart board. All too often this results in a bounce-out whereupon the needle of the dart is rejected by the wire in the dart board causing it to bounce off the wire and land on the floor where the dart game is being held. Another cause of dart rejection by the dart board occurs when the dart needle glances off such a wire, but lacks sufficient force to retain its penetration into the dart board cork or other needle receiving material. This is referred to as a "fall out." Bounce-outs and fall-outs score 0. Thus it is seen that even among the most skillful dart throwers, a single occurrence of a bounce-out (the term being used generically to include both bounce-outs and fall outs as previously described) can determine the winners of a match.
The wires on a dart board are approximately 0.056" to 0.062" in diameter. When said wire is viewed in cross section, it becomes evident that only the top 180 degrees of its circumference is subject to impact by dart points. A dart point striking the top dead center of said circumference has a high probability of resulting in a bounce-out. Any dart point striking said wire within an arc of 45 degrees on either side of top dead center is potentially subject to a bounce-out and the possibility of a fall-out due to loss of dart momentum as a result of striking said wire. The probability of a bounce-out decreases as the point of dart impact moves away from top dead center. The probability that a dart point, which impacts a wire more than 45 degrees from top dead center, will bounce or fall-out is very low. This observation must be tempered by noting that "top dead center" is a specific location with respect to the relationship of a wire to the dart board, whereas it is a variable location with respect to thrown darts which depends on the trajectory and attitude of said darts.
The main object of this invention is to provide a dart which reduces significantly the occurrence of all bounce-outs in the broad sense such as results from the dart needle either hitting directly on the center of a dart board wire or striking a glancing blow thereon and thereafter falling from the scoring area of the dart board.
A related objective of this invention is to provide a dart structure which minimizes bounce-outs by a dual action of causing the dart needle to retract within a cavity located in the dart body and rotate the point of the needle through an arc so that it will cause the needle point to strike the needle receiving cork or other medium of the dart board with sufficient remaining force to be embedded therein for scoring.
The problem of bounce-outs due to the needle point of the dart striking a dart board wire with either a direct or glancing strike has been present virtually ever since the game of darts was first played. The problem of bounce-out and fall-out is of so much concern to dart players that it is not surprising that there have been a wide variety of attempted solutions to this problem, some of which border on the extreme.
U.S. Pat. No. 3,976.298 issued to Hinchman discloses a dart which separates upon striking a dart board wire so as to enable the needle to remain in the board.
U.S. Pat. Nos. 1,893,787 to Schroeder, 2,119,524 issued to Ghar and 2,684,851 issued to Stokes, all disclose darts which explode so as to leave the needle in the dart board.
U.S. Pat. No. 4,101,126 issued to Kurtz, et al, discloses a game dart having a pivotally movable needle point which is mounted in the dart barrel section. The rearward portion of the dart needle is mounted within an aperture located in the forward part of the barrel section. The space between the aperture and the dart contains an elastomeric material permitting the point to flex or pivot upon striking a dart board wire. FIGS. 5 and 6 of the Kurtz, et al, patent illustrate the use of a spring attached directly to the rearward portion of the dart needle (20) to allow flexing of the dart needle point when contacting a metal rib, viz., dart board wire.
U.S. Pat. No. 4,109,915 issued to Bottelsen is directed to a breakaway dart with a body that breaks away from the point, viz., needle point, upon impact of the dart with the dart board. The stated objective of the Bottelsen breakaway dart is to minimize the size of the embedded dart in a target so that subsequent darts can be thrown to the high score area of the prior darts. Springs are employed to separate the point from the other parts of the dart and/or to hold the point in projected position during flight and to allow telescoping upon impact.
U.S. Pat. No. 4,181,303 issued to Kent Sjogren discloses a dart comprising an elongate body portion, a bore extending axially in said body portion, and a tip, viz., needle, arranged for axial movement in said board between first and second limit positions. Sjogren's dart body consists of two main parts which must be screwed together. The tip is encircled by a spring arranged in the elongate body portion. Flights are fitted to the end of the body remote from said needle tip and means may be provided for ejecting the flights of the darts upon axial movement of needle tip to its fixed limit position. Preferably the needle tip is able to move radially into the bore between preferred limits. The advantage stated for the Sjogren dart is that the number of rebounds occurring should the dart strike a dart board wire is greatly reduced in comparison with a standard dart. It will be noted from column 4, lines 30 to 49, that when a dart constructed in accordance with the Sjogren invention hits the central zone of a dart board wire, the velocity of the dart body will be lost and the dart will not enter the board. However, when a dart constructed in accordance with the Sjogren invention strikes the dart board wire in areas adjacent to the said central zone, the dart tip may stay in the target board owing to the low loss of kinetic energy after each bounce, sufficient energy remains to enable the dart needle tip to enter the board, provided that it passes the wire, viz., moves off the dart board wire and into the target medium. Note col. 4, 11. 50-67 of Sjogren. Sjogren's dart contains no mechanism to protect spring 10 from deterioration and crushing, viz., no way to limit the throw of the spring. Sjorgen apparently did not recognize the problem of spring deterioration on repeated usage of his dart and hence failed to illustrate a dart body structure capable of solving this problem.
U.S. Pat. No. 4,230,332 issued to Walter E. Bottelsen is directed to what is described as a no bounce dart having an elongate body with a dart needle point sliding in one end of the body and a tail carried at the other end of the body. The point is normally in an extended position on impact with a target, or an obstruction adjacent the target, the momentum of the body causes the point to slide in the body to a position where the body impacts the head of the needle point and hammers the needle point into the target past an obstruction, thereby reducing the likelihood of bounce of the dart.
British Pat. No. 1.593,047 issued to Brian Brooks is directed to a dart in which the dart needle point is replaceable, and which reduces the likelihood of the dart rebounding dangerously and the risk of damaging the point of the dart. In British Pat. No. 1593047, dart point (12) has a rear stepped diameter port in the stepped bore. Spring (28) lies in the larger diameter bore portion against the front of the boss of the flight part. The spring biases the point rear port against the bore shoulder. According to page 1, right column, lines 81 to 86 of this Brooks British patent, when in use spring (28) acts as a shock absorber and allows resiliently resisted axial displacement of dart needle point (18) on impact with a dart board, and thus reduces the risk of a dart rebounding dangerously when, for example, striking a dividing wire on the board. However, Brooks provides no means for limiting the extent to which his spring is compressed so that Brooks' dart body lacks the structure to retain the spring from losing its resiliency and protect it from being crushed upon repeated usage. Moreover, the Brooks dart requires an axial two diameter bore through the total length of the dart body thereby causing the dart body diameter to be larger than would otherwise be required for any given dart body weight. The larger the dart body diameter becomes, the more it constitutes an obstruction to following darts.
British Patent Application No. GB20268778A (Derwent Publications Ltd.) applicant and inventor, Cyril Cohen, discloses a dart (2) having a needle point (6) which is so mounted that the point can move laterally in any direction with respect to the remainder (4) of the dart. The dart point (6) is mounted within dart barrel (4) and is provided with a recess (8) and a rubber bush (10). The rubber bush sits in recess (8) of dart barrel (4) and locates the dart point (6) which can pivot laterally from side to side in the bush (10) with respect to the barrel (4). Alternatively, a double coil spring (14) can be located in the recess (8) in place of the rubber bush. Published Cyril Cohen British Patent Application GB2026878A is very similar to Kurtz et al U.S. Pat. No. 4,101,126.
None of these prior art patents discloses a dart having means to cause the point of a dart needle (which strikes the center of a dart wire) to rotate forcefully off the wire center and be deflected into the target when full impact of the dart occurs.